App.xaml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.ApplicationModel.AppService;
using Windows.ApplicationModel.Background;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

namespace ExtensionSample
{
    /// <summary>
    /// 提供特定于应用程序的行为，以补充默认的应用程序类。
    /// </summary>
    sealed partial class App : Application
    {
        /// <summary>
        /// 初始化单一实例应用程序对象。这是执行的创作代码的第一行，
        /// 已执行，逻辑上等同于 main() 或 WinMain()。
        /// </summary>
        public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;
        }

        private AppServiceConnection appServiceconnection;
        private BackgroundTaskDeferral appServiceDeferral;
        private AppServiceConnection appServiceConnection;

        protected override async void OnBackgroundActivated(BackgroundActivatedEventArgs args)
        {
            base.OnBackgroundActivated(args);
            IBackgroundTaskInstance taskInstance = args.TaskInstance;
            AppServiceTriggerDetails appService = taskInstance.TriggerDetails as AppServiceTriggerDetails;
            appServiceDeferral = taskInstance.GetDeferral();
            taskInstance.Canceled += OnAppServicesCanceled;
            appServiceConnection = appService.AppServiceConnection;
            appServiceConnection.RequestReceived += OnAppServiceRequestReceived;
            appServiceConnection.ServiceClosed += AppServiceConnection_ServiceClosed;
        }

        private async void OnAppServiceRequestReceived(AppServiceConnection sender, AppServiceRequestReceivedEventArgs args)
        {
            AppServiceDeferral messageDeferral = args.GetDeferral();
            ValueSet message = args.Request.Message;

            message.TryGetValue("q", out var obj);

            if (obj is string command)
            {
                ValueSet returnData = new ValueSet();

                switch (command)
                {
                    case "lyric":

                        var title = message["title"] as string;
                        message.TryGetValue("artist", out object art);
                        var artists = art as string;

                        returnData.Add("result", "My Lyric Extension Works Well!");
                        returnData.Add("status", 1);
                        break;

                    case "online_music":
                        var action = message["action"] as string;
                        switch (action)
                        {
                            case "search":
                                message.TryGetValue("page", out object page);
                                message.TryGetValue("count", out object count);
                                var key = message["keyword"] as string;

                                break;
                            case "song":
                                var song = message["id"] as string;

                                break;
                            case "album":
                                var album = message["id"] as string;

                                break;
                            case "artist":
                                var artist = message["id"] as string;
                                break;
                            default:
                                break;
                        }

                        break;
                    default:
                        returnData.Add("status", 0);
                        break;
                }


                await args.Request.SendResponseAsync(returnData);
                // Return the data to the caller.
                // Complete the deferral so that the platform knows that we're done responding to the app service call.
                // Note for error handling: this must be called even if SendResponseAsync() throws an exception.
            }
            else
            {
                await args.Request.SendResponseAsync(new ValueSet()
                {
                    ["status"] = 0
                });
            }

            messageDeferral.Complete();
        }

        private void OnAppServicesCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
        {
            appServiceDeferral.Complete();
        }

        private void AppServiceConnection_ServiceClosed(AppServiceConnection sender, AppServiceClosedEventArgs args)
        {
            appServiceDeferral.Complete();
        }

        /// <summary>
        /// 在应用程序由最终用户正常启动时进行调用。
        /// 将在启动应用程序以打开特定文件等情况下使用。
        /// </summary>
        /// <param name="e">有关启动请求和过程的详细信息。</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
            Frame rootFrame = Window.Current.Content as Frame;

            // 不要在窗口已包含内容时重复应用程序初始化，
            // 只需确保窗口处于活动状态
            if (rootFrame == null)
            {
                // 创建要充当导航上下文的框架，并导航到第一页
                rootFrame = new Frame();

                rootFrame.NavigationFailed += OnNavigationFailed;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: 从之前挂起的应用程序加载状态
                }

                // 将框架放在当前窗口中
                Window.Current.Content = rootFrame;
            }

            if (e.PrelaunchActivated == false)
            {
                if (rootFrame.Content == null)
                {
                    // 当导航堆栈尚未还原时，导航到第一页，
                    // 并通过将所需信息作为导航参数传入来配置
                    // 参数
                    rootFrame.Navigate(typeof(MainPage), e.Arguments);
                }
                // 确保当前窗口处于活动状态
                Window.Current.Activate();
            }
        }

        /// <summary>
        /// 导航到特定页失败时调用
        /// </summary>
        ///<param name="sender">导航失败的框架</param>
        ///<param name="e">有关导航失败的详细信息</param>
        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
        }

        /// <summary>
        /// 在将要挂起应用程序执行时调用。  在不知道应用程序
        /// 无需知道应用程序会被终止还是会恢复，
        /// 并让内存内容保持不变。
        /// </summary>
        /// <param name="sender">挂起的请求的源。</param>
        /// <param name="e">有关挂起请求的详细信息。</param>
        private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            //TODO: 保存应用程序状态并停止任何后台活动
            deferral.Complete();
        }
    }
}